This proposal seeks support for secondary analyses of two longitudinal data sets to clarify developmental and contextual processes linking reading skill development to risk for and indicators of depressive symptoms, externalizing behavior problems and shy-withdrawn behavior problems from Grade 1 to Grade 4. Longitudinal data will be analyzed from Cohorts 1 and 2 of the Baltimore Prevention Project (BPP), an experimental evaluation of two preventive interventions delivered in Grades 1 and 2. Data will be analyzed for children who were assigned to the control (non-intervention) conditions. These children participated in a naturalistic longitudinal study beginning in Grade 1. The first aim is to use data from BPP Cohort 1 (N = 684) to clarify the associations between reading skill development and the development of (a) concentration problems, (b) depressive symptoms, (c) extemalizing behavior problems and (d) shy-withdrawn behavior problems. Growth curve models will be used to test whether concentration problems and depressive symptoms mediate the association between reading skill growth and growth in extemalizing behavior problems and shy-withdrawn behavior; and to test whether these effects differ by gender. The second aim is to clarify whether differing classroom contexts alter the developmental significance of different patterns of reading skill development from Grade 1 to Grade 4. The third aim is to replicate findings from Cohort 1 using data from BPP Cohort 2 (N = 655). Results will contribute to basic knowledge about how children's performance in the central learning task of early elementary school (learning to read) contributes to risk for psychopathology; and how individual characteristics and the classroom ecology may moderate those processes. Results will also provide an empirical basis for estimating the potential impact of interventions targeted at reading skills on children's overall risk for mental health problems in the elementary school years; and will identify potential mediators and moderators of intervention effects.